A multi-window system, in which plural windows can be displayed, is known. In a case where the multi-window system is applied to an electronic device such as a mobile phone, an operation to select a window can be inconvenient. For example, in an electronic device that does not have a pointing device such as a mouse for selecting a position (coordinate), an operation to select a desired window is likely to be inconvenient if the number of windows displayed increases.
Also, in a case of an electronic device such as a mobile phone that has a small display area, if all displayable windows are displayed, the size of each window has to be smaller, which makes it difficult for a user to recognize a content of each window. Conversely, if each window is displayed in an appropriate size so that a user is able to recognize a content of the window, not all displayable windows can be displayed, and only some of the windows is displayed. As described in the foregoing, if the multi-window system is applied to an electronic device having a small display area, a case may occur in which it is difficult for a user to select a desired window from among plural windows.
As a technique for improving operability in the multi-window system, a technique described in JP 2003-280630 A and JP 2007-122633 A is known. The technique described in JP 2003-280630 A and JP 2007-122633 A is a technique by which a special window is displayed in a display area and displayed in the special window is an overhead screen showing the arrangement of all windows including any hidden windows.